Solutions · Rubber Compounding
Rubber compounding runs on fillers: carbon black, silica, and mineral fillers – light, dusty powders that have to reach the mixer reliably and in the right amount. PW Silo Systems designs aluminum and stainless steel silos for rubber fillers with you – with discharge aids, dust collection, and clear product separation.
Rubber Filler Storage at a Glance
A rubber filler silo stores carbon black, silica, calcium carbonate, kaolin, or other fillers and additives close to the mixing line – for tires, technical rubber goods, hoses, seals, or profiles. It keeps the filler dry and contained and feeds it in a controlled way to weighing and mixing.
Fillers range from very light powders such as carbon black and precipitated silica to denser mineral fillers. They dust, bridge, and must not be mixed by accident. Silo geometry, discharge, and dust collection are therefore designed together with you for your fillers and your compounding process.
Why Rubber Fillers Are Demanding
Black dust, light powders, and many different fillers decide whether a compounding silo plant runs reliably.
Carbon black dust escapes through every leak and leaves black traces on equipment, buildings, and products.
Carbon black and precipitated silica have a low bulk density. They behave differently in filling, venting, and discharge.
Fine mineral fillers such as calcium carbonate and kaolin compact under their own weight and build bridges over the outlet.
A compounding plant often uses several carbon black grades, silica, and mineral fillers that must be kept strictly separate.
Lot-to-lot differences in filler properties show up in the compound.
Venting, filtration, and explosion protection depend on the filler and its particle size.
Silo Materials
We build silos exclusively in aluminum and stainless steel. Carbon steel is not an option for us: its coating is the only protection against corrosion – and flaking coating or rust can end up in your compound.
Which of our two materials fits your filler silo depends on the product, your process, and your site. We select the material and the design with you.
Your Rubber Filler Silo System
Silo, discharge, blending, filtration, and monitoring are engineered as one system. That means fewer interfaces for your team and components that are designed to work together.
Storage
Concentric mass-flow discharge without asymmetric flow zones – as standard, site-assembled, indoor, or multi-compartment silos.
Learn moreBlending
Gravity blending and homogenizing with four technologies, including PW ConeBlend with a hopper that is quick to clean.
Learn moreDischarge
Air fluidization for uniform discharge of poorly flowing products – prevents bridging and can be retrofitted to existing silos.
Learn moreDischarge
Vibration from unbalanced motors breaks up cohesive forces, resolves caking, and keeps the outlet clear.
Learn moreFiltration
Dust separation during pneumatic filling and conveying – sized for fine powders.
Learn moreMonitoring
Level measurement for reliable monitoring of the silo content – so you know when to reorder.
Learn moreFillers & Additives
Products marked “Tested in our lab” are on our list of bulk materials. The others we review with you based on your material data before designing the silo.
Tested in our lab
Carbon black, rubber-grade carbon black, furnace black
Carbon black is on our list of bulk materials tested in our lab. Venting, filtration, and a closed system keep black dust contained.
Tested in our lab
Precipitated silica, silica filler, white reinforcing filler
Precipitated silica is on our tested list. Its very light, fine particles are considered in hopper design and dust collection.
Tested in our lab
Calcium carbonate, ground calcium carbonate, whiting
Calcium carbonate is on our tested list. Discharge aids are planned for this fine, cohesive filler.
Tested in our lab
Kaolin, kaolin clay, china clay
Kaolin is on our tested list. Outlet and discharge are designed for its flow behavior.
Review with us
Zinc oxide, ZnO, activator
Zinc oxide is used as an activator in rubber compounds. We review your product data with you before designing the silo.
Review with us
Sulfur, rubber-grade sulfur
Sulfur is used for vulcanization. Product-specific safety requirements for your site we review with you.
Also tested in our lab:
Send us your material data and we will review the right solution with you:
Filler Check
Type in your filler or any other bulk material to see whether it has already been tested in our lab. The list covers 287 bulk materials.
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Service in the U.S.
With more than 40 years of experience in silo engineering, we support your rubber filler silo project from the first design discussion to commissioning. We deliver to every U.S. state and install with our own qualified personnel.
FAQ
Answers to the questions plant managers, engineers, and buyers ask most often about storing rubber fillers and additives in silos.
Dry fillers and additives for rubber compounding can be stored in a properly designed silo. These products are on our list of bulk materials tested in our lab:
Zinc oxide, sulfur, and other rubber chemicals we review with you based on your material data.
A closed system for filling and discharge, integrated filters, and PW FilterLine dust collectors keep carbon black dust inside the system. Filter size and venting are matched to your filling rate and your product.
Carbon black and precipitated silica have a low bulk density. They behave differently in filling, venting, and discharge than denser mineral fillers. Hopper geometry, venting, and discharge equipment are designed for the filler you use.
We recommend a dedicated silo per filler – or PW StoreLine multi-compartment silos that keep several products separate in one silo.
In mass flow, the entire silo content moves downward when material is discharged – not just a channel in the center. Your rubber fillers leaves the silo in the order it came in (first in, first out), and no product is left behind in dead zones. Our PW StoreLine silos are designed for concentric mass-flow discharge without asymmetric flow zones.
We build silos exclusively in aluminum and stainless steel – never in coated carbon steel, so no flaking coating or rust can contaminate your compound. Which of our two materials fits depends on the product, your process, and your site. We select it with you.
The right size depends on your daily consumption, delivery intervals, the number of products, and the space available at your site. PW StoreLine silos are available in a wide range of sizes and diameters, and silos too large for road transport are assembled on site. We size the system with you – without oversized investment.
Yes. We deliver to every U.S. state and support your project with silo transport, field assembly, silo installation and supervision, and site relocation of existing systems.
Very likely. Our silo systems are designed for nearly all free-flowing, granular, and powdered bulk solids. Send us your material details – particle size, bulk density, moisture, and how the product is filled and discharged – and we will review the right storage solution with you.
Tell us about your products, required storage capacity, how the silo is filled and discharged, and your site conditions. Based on this, we work out the material, silo type, and configuration with you and send you a detailed quote.
